Muscle oxygenation, endocrine and metabolic regulations during low - intensity endurance exercise with blood flow restriction

Muscle oxygenation, endocrine and metabolic regulations during low - intensity endurance exercise with blood flow restriction

The present study investigated the effect of endurance exercise with Blood flow restriction (BFR) under two different types of low-intensity (either 25% or 40% of VO2 max) on muscle oxygenation, energy metabolism and endocrine responses. Ten males were recruited for the present study. The three trials consisted of (1) endurance exercise at 40% of VO2 max without BFR (NBFR40), (2) endurance exercise at 25% of VO2 max with BFR (BFR25), and (3) endurance exercise at 40% of VO2 max with BFR (BFR40). During 15 min exercise in each trial. In BFR25 and BFR40, 2 min of pressure phase followed by 1 min of release phase were repeated five times throughout 15 min of exercise. During 15 min of exercise, we measured muscle oxygenation, respiratory gas. The blood samples were collected before exercise, immediately after 15 min of exercise, and 15, 30, and 60 min after completion of exercise. Deoxy-Hb during exercise was significantly higher in BFR25 and BFR40 compared with NBFR40. The BFR40 also presented significantly higher total-Hb than NBFR during 2 min pressure phase. Moreover, exercise-induced lactate elevation and pH reduction were significantly augmented in BFR40, with concomitant increased serum cortisol concentrations after exercise. In BFR40, carbohydrate (CHO) oxidation was significantly higher than those in NBFR40 and BFR25, whereas fat oxidation was inversely lower in BFR40. Deoxy-Hb and total Hb were significantly increased during 15min of pedaling exercise in BFR25 and BFR40, indicating augmented local hypoxia and blood volume (blood perfusion) in muscle. Moreover, low-and moderate-intensity exercise with BFR facilitated CHO oxidation.

The present study investigated the effect of endurance exercise with Blood flow restriction (BFR) under two different types of low-intensity (either 25% or 40% of VO2 max) on muscle oxygenation, energy metabolism and endocrine responses. Ten males were recruited for the present study. The three trials consisted of (1) endurance exercise at 40% of VO2 max without BFR (NBFR40), (2) endurance exercise at 25% of VO2 max with BFR (BFR25), and (3) endurance exercise at 40% of VO2 max with BFR (BFR40). During 15 min exercise in each trial. In BFR25 and BFR40, 2 min of pressure phase followed by 1 min of release phase were repeated five times throughout 15 min of exercise. During 15 min of exercise, we measured muscle oxygenation, respiratory gas. The blood samples were collected before exercise, immediately after 15 min of exercise, and 15, 30, and 60 min after completion of exercise. Deoxy-Hb during exercise was significantly higher in BFR25 and BFR40 compared with NBFR40. The BFR40 also presented significantly higher total-Hb than NBFR during 2 min pressure phase. Moreover, exercise-induced lactate elevation and pH reduction were significantly augmented in BFR40, with concomitant increased serum cortisol concentrations after exercise. In BFR40, carbohydrate (CHO) oxidation was significantly higher than those in NBFR40 and BFR25, whereas fat oxidation was inversely lower in BFR40. Deoxy-Hb and total Hb were significantly increased during 15min of pedaling exercise in BFR25 and BFR40, indicating augmented local hypoxia and blood volume (blood perfusion) in muscle. Moreover, low-and moderate-intensity exercise with BFR facilitated CHO oxidation.